Tremulant for stringed musical instruments



M. L. LOHMAN TYREMULANT FOR STRINGED MUSICAL INSTRUMENTS Nov. 15, 1938 2 Sheets-Sheet 1 Filed June 28, 1937 INVENTOR. Ma w/v A. LOHM/I/V.

ATTORNEY Nov. 15, 1938.

TREMULANT FOR STRINGED MUSICAL INSTRUMENTS Filed June 28, 1957 2 Sheets-Sheet 2 I F r I 41/21 w/v Z Z ZZ 3 BY 0 114A ATTORNEY.

M. L. LOHM'AN- 2,136,627 I Patented Nov. 15 1938 UNITED STATES PATENT OFFIQE TREMULANT FOR STRINGED MUSICAL I INSTRUMENTS This invention relates to a stringed musical instrument, more particularly to a type of instrument such as a guitar. In the usual guitar, the tone produced is a single smooth tone wave. A

tremolo effect can be obtained by a movement of the fingers upon the strings. Such a movement is exceedingly difiicult to produce, especially when playing a plurality of strings or cords simultaneously, and can only be obtained by the most skilled musicians.

The principal object of this invention is to provide means for producing a tremolo in the tone of a stringed instrument Without requiring any skill on the part of the musician or any movement of his fingers. I

Another object of the invention is to provide a tremulant for stringed instruments in which the tremolo frequency can be varied to suit the particular composition being played, and so that the 0 variations in frequency can beaccomplished while playing without the use of the hands of the player.

A further object is to provide a construction which will impart a mechanical vibration to the strings of a stringed instrument without imparting any extraneous mechanical noises.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efficiency. These will become more apparent from the following description.

In the following detailed description of the in vention reference is had to the accompanying drawings which form a part thereof. Like numerals refer to like parts in all views of the drawings and throughout the description.

In the drawings:- 7 v Fig. 1 illustrates a typical guitar with the invention applied thereto.

Fig. 2 is a cross section therethrough, taken on the line of the bridge thereof.

Fig. 3 is a detail section through the improved bridge, taken on the line 3-3, Fig. 2.

Fig. 4 is a bottom view of the upper bridge plate, taken on the line 4-4, Fig. 2.

Fig. 5 is a fragmentary cross section through a similar guitar, illustrating an alternate form of the invention.

Fig. 6 is a detail view of the tailpiece employed in the invention.

Fig. 7 is a longitudinal section through an alternate form of bridge.

Fig. 8 is a cross section therethrough, taken on the line 88, Fig. 7.

Fig. 9 is a cross section through the bridge of Fig. 5, taken on the line 9-9, Fig. 5.

Fig. 10 is a plan view of the motor mechanism employed'with the form of Fig. 5.

Fig. 11 is a side view of the motor mechanism.

In the drawings a typical guitar is indicated at Iil with its neck at II, and its strings at I2. 5;

The invention comprises a vibrating or reciprocating bridge for supporting the strings I2.

This bridge consists of an upper bridge member I3 shapedalong its upper face similar to any of the usual guitar bridges, that is, it has a saddle mi bar I4 over which the strings pass and a separating ridge I5 for holding the strings in their proper separated positions. A lower bridge member I6 is secured to the front of the guitar immediately below the upper bridge member I3. 15'.

A roller plate I'I covers the lower bridge member I6, and an upper plate I8 is secured along the bottom of the upper bridge member I3. The upper plate I8 is preferably flanged as shown at II! to extend downwardly along each side of the 20.

lower bridge member I6. A pair of roller bearings 20 separate the two plates [1 and I8.

In Fig. 4, a bottom view of the upper plate I8 is illustrated. It will be noted that the plate is provided with roller channels 2I for holding the rollers 20 in place. At its midpoint it is provided with a pocket 22 for the reception of an eccentric disc 23.

The disc 23 is carried on the upper extremity of a shaft 24 which extends from a bearing frame 3o 25 within the sound box through the top thereof, through the lower bridge member I6, and through a bearing opening in the plate II. To minimize vibration, the bearing frame 25 is preferably mounted upon a suitable cross bar or bracket 26 35- extending between the sides of the sound box.

The frame supports a small electric motor 2'5 of the quiet, slow speed type. The motor, through the medium. of a worm 28, drives a worm gear 29, which is secured on the eccentric shaft 24. Current is fed to the motor 21 through suit able conductors 30 extending from a plug rcceptacle 3| in the side wall of the guitar.

It can be readily seen that as the motor 2'I rotates the worm 28, it will rotate the shaft 24 at a 4 5;

slower speed. The shaft 24 will rotate the eccentric 23 within the pocket 22 to cause the upper bridge member to vibrate laterally. This creates a regular cycle of varying tension in the strings I2, which will give a vibratory or tremolo effect to 50 the string tones.

The rapidity of the Vibration can be varied by means of a variable rheostat 32 operated from a foot treadle 33, and connected by means of a suitable electric cord 34 to the plug receptacle 3I. 55

The operator can, by varying the pressure of his foot, obtain various frequencies in the tremolo tone.

To accommodate the transverse vibration of the bridge, it is preferred to employ a pivoted tailpiece, such as shown in Fig. 6. The tailpiece consists of an attachment bracket 31, which is secured to the end of the guitar in the usual manner. A tailpiece 38 is pivoted to the bracket 31 upon a suitable pivot pin 39 to allow the strings to swing laterally with the reciprocation of the bridge.

In Figs. 7 and 8, an alternate form of the invention is illustrated in which the rollers are eliminated, and an upper bridge 40 slides directly upon the lower bridge 4|. In this form, a pin 42 extends downwardly from the upper bridge through a slot 43, and terminates in a slotted extremity 44 that rides upon a crank pin or eccentric pin 45. It can be readily seen that as the pin 45 is rotated, it will impart a reciprocation to the upper bridge 45, as in the preceding form.

In Figs. 5, 9, 10, and 11, still another form of the invention is illustrated. In this form, a bridge 45 is carried upon an L-shaped slide 41 which is secured to the top of the guitar. A tongue and groove construction as illustrated in Fig. 9 is employed to hold the bridge in place, yet allow it to slide longitudinally. One extremity of a flexible hollow shaft 48 is secured to the extremity of the slide 41 by means of suitable lock nuts 49. A piano wire 55 extends through the flexible shaft and is secured to the bridge 46. The wire 50 is reciprocated by means of the motor mechanism illustrated in Figs. 10 and 11, in which an electric motor 5| rotates a crank member 52 through the medium of suitable worm gear transmission members 53. The crank member 52 contains a series of threaded crank pin openings 54 into any desired one of which a crank pin screw 55 may be threaded. The extremity of the wire 50 terminates at the screw 55. The extremity of the flexible shaft 48 terminates in a bracket 56 supported from a motor base 51. It can be seen that the motor will rotate the crank member 52, and impart a reciprocation to the wire 50, which will in turn reciprocate the bridge 46 for the purposes above set forth.

The last described form of the invention removes the motor and all rotating parts from the guitar so that the operation of the invention is noiseless.

The threaded crank pin holes 54 are placed at different distances from the axis of the crank member 52 so that by changing the screw 55 to various holes, an adjustment can be had in the length of the reciprocation imparted to the wire 50 It is probably possible to provide other means and mechanisms for vibrating the bridge laterally of the axis of the strings. The above means are simply illustrative of certain of these mechanisms.

It is desired to be understood that these various means are within the scope of this invention. While the invention has been described as applied to a guitar, it would operate on any stringed instrument such as a piano.

While a specific form of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied, within the scope of the appended claims, without departing from the spirit of the invention.

Having thus described the invention, what is claimed and desired secured by Letters Patent is:

1. In a stringed musical instrument of the type having strings stretched over a bridge member, means for producing a tremolo effect in the tones of said strings comprising: means for supporting said bridge so that it may move transversely; and means for imparting a reciprocatory movement to said bridge in a plane parallel to the plane of said strings and in a direction transverse to the normal axis of said strings.

2. In a stringed musical instrument of the type having strings stretched over a bridge member, means for producing a tremolo effect in the tones of said strings comprising: a slide member for supporting said bridge so that it may move laterally of said strings; and means for reciprocating said bridge sideways on the front face of said instrument.

3. In a stringed musical instrument of the type having strings stretched over a sound box, means for imparting a tremulant effect to the tone of said strings comprising: a lower bridge member secured to said sound box beneath said strings; an upper bridge member movably mounted on and supporting said strings over said lower bridge member; and means for reciprocally moving said upper bridge member on said lower bridge member to produce a vibratory tension in said strings.

4. In a stringed musical instrument of the type having strings stretched over a sound box, means for imparting a tremulant effect to the tone of said strings comprising: a lower bridge member secured to said sound box beneath said strings; an upper bridge member movably mounted on and supporting said strings over said lower bridge member; means for reciprocally moving said upper bridge member on said lower bridge member to produce a vibratory tension in said strings; and guide members for holding the upper and lower bridge members in alignment with each other.

5. In a stringed musical instrument of the type having strings stretched over a sound box, means for imparting a tremulant effect to the tone of said strings comprising: a lower bridge member secured to said sound box beneath said strings; an upper bridge member movably mounted on and supporting said strings over said lower bridge member; guide means on said bridge members for guiding the movement of said upper bridge member in a direction transverse to the axis of said strings; a motor operated reciprocating mechanism; and means for transmitting the movements of said latter mechanism to said upper bridge member to reciprocate the latter on said lower bridge member.

MELVIN L. LOHMAN. 

